Hydraulic Blocking Rotary Actuator
In one embodiment, a hydraulic blocking rotary actuator including a stator housing having a through bore to position a rotor assembly. A rotor assembly includes an output shaft and at least one rotary piston disposed radially about the output shaft. The rotary piston includes an integral first vane element and an integral second vane element each with peripheral longitudinal faces substantially concentric to the other. A continuous seal groove is disposed in peripheral longitudinal faces and lateral end faces of the rotary pistons. A continuous seal is disposed in the continuous seal groove. The bore through the stator housing includes an interior cavity with surfaces adapted to receive the rotor assembly. With rotation fluid ports blocked the housing cavity is sealed with the continuous piston seal for hydraulic blocking, preventing actuator displacement by external forces. Other embodiments are disclosed.
Latest WOODWARD, INC. Patents:
This invention relates to an actuator device and more particularly to a pressurized hydraulic blocking rotary actuator device wherein piston assemblies disposed about the rotor are moved by fluid under pressure.
BACKGROUNDRotary actuators are used as part of some mechanical devices, to deliver rotary motion in an efficient manner and with the capability to maintain rotary position by blocking the hydraulic power fluid source. The ability to maintain a rotary position is desirable to control aircraft flight control surfaces and for other applications such as rotary valve assemblies. Rotary actuators are desirable because they maintain constant torque and conserve space. Such prior art rotary actuators typically include multiple subcomponents such as a rotor and two or more stator housing components. These subcomponents generally include a number of seals intended to prevent leakage of fluid out of the housing and/or between hydraulic chambers of such rotary valve actuators. Because of this leakage, prior art rotary actuators cannot maintain position by merely blocking the hydraulic power source, but maintain position by supplying additional make up fluid and constant control.
SUMMARYIn general, this document describes hydraulic blocking rotary actuators with continuous seals disposed on peripheral surfaces of the pistons.
In a first aspect, a hydraulic blocking rotary actuator includes a stator housing having a bore disposed axially therethrough. A rotor assembly includes an output shaft and at least one rotary piston assembly disposed radially about the output shaft. The rotary piston assembly includes integral first vane element and a second vane element protruding radially along the axis at opposite ends, said piston having a circumferential surface portion adapted to connect to the output shaft when each of the pistons are disposed about the output shaft, a first peripheral longitudinal face and a second longitudinal face, a first lateral peripheral face and a second peripheral face, each of said pistons adapted to be assembled to a longitudinal axis of the output shaft. A first continuous seal groove is disposed in the first and second peripheral longitudinal face and the first and second lateral face of each of the first and second vane elements of a piston. A continuous seal is disposed in the continuous seal groove. The bore of the stator housing includes a seamless interior surface adapted to receive the rotor assembly and said interior surface adapted to contact the continuous seal when the rotor assembly is rotated inside of the longitudinal bore.
Implementations can include some, all, or none of the following features. The first vane element and the second vane element can be disposed circumferentially adjacent to each other. Each of the first and second vane elements can be adapted so that a rotary piston may pass through the first end bore before being assembled to the output shaft. The actuator can also include a second rotary piston assembly disposed radially about the output shaft, the second rotary piston assembly including a third vane element and a fourth vane element, the second rotary piston having a portion adapted to connect to the output shaft when each of the rotary pistons are disposed radially about the output shaft, a first peripheral longitudinal face and a second longitudinal face, a first lateral peripheral face and a second peripheral face, the second rotary piston adapted to be assembled to a longitudinal axis of the output shaft, a second continuous seal groove disposed in the first and second peripheral longitudinal face and the first and second lateral face of the second rotary piston, and a second continuous seal disposed in the second continuous seal groove. The first rotary piston and the second rotary piston assembly can be disposed opposite each other about the output shaft. Each of said third and fourth vane elements integral to the second rotary piston can be adapted to pass through the first end bore before being assembled to the output shaft. Each rotary piston assembly installed in the stator housing can define separate pressure chambers inside of the middle bore portion. The continuous seal can be an O-ring, an X-ring, a Q-ring, a D-ring, an energized seal, or combinations of these and/or any other appropriate form of seal. The bore disposed axially therethrough can include a first end bore portion and a second end bore portion, the first end bore portion and said second end bore portions having a first diameter and at least a middle bore portion disposed between the first end bore portion and the second end bore portion, the middle bore portion having a second diameter larger than the first diameter, the middle bore portion can also include a cylindrical recess disposed coaxial with the middle bore portion, the cylindrical recessed sector having a diameter larger than the diameter of the middle bore portion, said cylindrical recess adapted to receive the vanes of the rotor assembly. A first external pressure source can provide a rotational fluid at a first pressure for contacting the first vane of the rotary piston assembly and a second external pressure source provides a rotational fluid for contacting the second vane of the rotary piston assembly. Opposing pressure chambers defined by the housing and rotor can have equal surface areas as the rotor rotates within the housing. The output shaft can be configured to connect to a hinge of a flight control surface. The stator housing can be adapted for mounting on a stationary wing. The bore can include a first opposing arcuate ledge disposed radially inward along the perimeter of the bore, the first ledge having a first terminal end adapted to contact the first vane of the rotary piston assembly and a second terminal end of the first arcuate ledge adapted to contact the second vane of the rotary piston assembly. The middle bore portion can include a second arcuate ledge disposed radially inward along the perimeter of the middle bore portion and opposite the first arcuate ledge, the second ledge having a first terminal end adapted to contact the first vane of the second rotary piston assembly and a second terminal end of the second arcuate ledge adapted to contact the second vane of the second rotary piston assembly. The rotary pistons of the rotor assembly and the arcuate ledges can be configured to define multiple pressure chambers. Opposing pressure chambers defined by the housing and rotary pistons can have equal surface areas as the rotor assembly rotates within the housing. A first opposing pair of the pressure chambers can be adapted to be connected to an external pressure source and a second opposing pair of the pressure chambers can be adapted to be connected to a second external pressure source. A first external pressure source can provide a rotational fluid at a first pressure for contacting the first vane of the first rotary piston assembly and the second external pressure source can provide a rotational fluid for contacting the first vane of the second rotary piston assembly. The first terminal end can also include a first fluid port formed therethrough and the second terminal end can include a second fluid port formed therethrough and the first fluid port can be connected to a rotational fluid provided at a first pressure and the second fluid port can be connected to a rotational fluid provided at a second pressure. The bore can be formed in a single seamless housing member.
In a second aspect, a method of rotary actuation includes providing a rotor assembly that includes an output shaft and at least one rotary piston assembly disposed radially about the output shaft, said rotary piston assembly including a first vane element and a second vane element. The first vane element and second vane element each has a portion adapted to connect to the output shaft when each of the vane elements is disposed radially about the output shaft, a first peripheral longitudinal face and a second longitudinal face, and a first lateral peripheral face and a second peripheral face, each of said vane elements adapted to be assembled to a longitudinal axis of the output shaft, a first continuous seal groove disposed in the first and second peripheral longitudinal face and the first and second lateral face of each of the first and second vane elements, and a continuous seal disposed in the continuous seal groove. A stator housing is provided having a bore including an opposing pair of arcuate ledges disposed radially inward along the perimeter of the bore, each of said ledges having a first terminal end and a second terminal end. A rotational fluid is provided at a first pressure and contacting the first vane element of the rotary piston assembly with the first rotational fluid. A rotational fluid is provided at a second pressure less than the first pressure and contacting the second vane element of the rotary piston assembly with the second rotational fluid. The rotor assembly is rotated in a first direction of rotation.
Various implementations can include some, all, or none of the following features. The second pressure can be increased and the first pressure can be decreased until the second pressure is greater than the first pressure, rotating the rotor assembly in an opposite direction to the first direction of rotation. The rotation of the rotor assembly in the opposite direction can be stopped by contacting the first terminal end of the first ledge with the second vane element of the rotary piston assembly and contacting the second terminal end of the first ledge with the first vane element of the rotary piston assembly. The rotary piston assemblies can isolate the rotational fluid into a first opposing pair of chambers and a second opposing pair of chambers, and the method can also include providing the first rotational fluid at the first pressure to the first opposing pair of chambers, and providing the second rotational fluid at the second pressure to the second opposing pair of chambers. The first terminal end can further include a first fluid port formed therethrough and the second terminal end can include a second fluid port formed therethrough, and wherein providing the rotational fluid at a first pressure can be provided through the first fluid port and providing the rotational fluid at a second pressure can be provided through the second fluid port. The method can also include stopping the rotation of the rotor assembly by at least one of contacting the first terminal end of the first ledge with the first vane element, and contacting the second terminal end of the first ledge with the second vane element.
In a third aspect, a hydraulic blocking actuator includes a stator housing having a bore disposed axially therethrough, a first static piston assembly and a second static piston assembly, each static piston assembly having an outer longitudinal half cylindrical peripheral surface adapted to contact an inner cylindrical wall of a portion of the stator housing. Each static piston assembly includes two interior partial cylindrical surfaces, a single radial inwardly disposed vane positioned between the two interior partial cylindrical surfaces, and two radial inwardly disposed half vanes positioned at the distal ends of the two interior partial cylindrical surfaces, wherein the first static piston assembly and the second static piston assembly are disposed with one of the half vanes of the first static piston assembly adjacent longitudinally to one of the half vanes of the second static piston assembly and the other half vane of the first static piston assembly adjacent longitudinally to the other half vane of the second static piston assembly, and wherein each of the vanes has a first inwardly disposed peripheral longitudinal face and a first lateral peripheral face and a second lateral peripheral face. At least four continuous seal grooves are included, each of said seal grooves being disposed in a pathway along each of the first peripheral longitudinal face and the first lateral face and second lateral face of each of the vane elements, and at least four continuous seals disposed in each of the at least four continuous seal grooves. The hydraulic blocking actuator also includes a rotor adapted to be received in the bore of the housing.
Various implementations can include some, all, or none of the following features. The rotor can include a first end section and a second end section and a middle section disposed between the first end section and the second end section; said first and second end sections being formed about the axis of the rotor and having a diameter adapted to be received in the bore of the housing, said middle section having a first diameter formed about the axis of the rotor with a radial diameter smaller than the diameter of the end sections, said middle sections further including a second diameter formed in the first diameter about the axis of the rotor as an opposing pair of substantially quarter-sectional recesses. The single radial vane can extend an inward perpendicular distance from the two interior partial cylindrical surfaces such that portions of the continuous seals disposed in the continuous seal grooves in the longitudinal face of the single vane can contact the first diameter of the rotor and the half vanes can extend an inward perpendicular distance from the two partial cylindrical surfaces such that portions of the continuous seals disposed in the continuous seal grooves in the longitudinal face of the half vanes can contact with the second diameter of the rotor. The single vane assembly of the first static piston assembly and the single vane assembly of the second static piston assembly can be disposed opposite each other inside the middle bore portion of the stator housing. Two adjacent half vane assemblies can be disposed opposite two other adjacent half vane assemblies inside the middle bore portion of the stator housing. The first static piston assembly and the second static piston assembly, and the rotor can define four pressure chambers. Opposing pressure chambers can have equal surface areas as the rotor rotates within the housing. The output shaft can be configured to connect to a rotary valve stem or flight surface. The stator housing can be adapted for connection to a valve housing. The continuous seal can be an O-ring, an X-ring, a Q-ring, a D-ring, an energized seal, or combinations of these and/or any other appropriate form of seal. A first opposing pair of the pressure chambers can be adapted to be connected to an external pressure source and a second opposing pair of the pressure chambers can be adapted to be connected to a second external pressure source.
In a fourth aspect, a method of rotary actuation includes providing a rotary actuator including a stator housing having a longitudinal bore disposed axially therethrough, the bore having a first end bore portion and a second end bore portion and at least a middle bore portion disposed between the first end bore portion and the second end bore portion, a first static piston assembly and a second static piston assembly, each static piston assembly having an outer longitudinal half cylindrical peripheral surface adapted to contact an inner cylindrical wall of the middle bore portion of the static piston housing. Each static piston assembly includes two interior partial cylindrical surfaces, a single radial inwardly disposed vane positioned between the two interior partial cylindrical surfaces, and two radial inwardly disposed half vanes positioned at the distal ends of the two interior partial cylindrical surfaces, wherein the first static piston assembly and the second static piston assembly are disposed in the middle bore portion with one of the half vanes of the first static piston assembly adjacent longitudinally to one of the half vanes of the second static piston assembly and the other half vane of the first static piston assembly adjacent longitudinally to the other half vane of the second static piston assembly, and wherein each of the vanes has a first inwardly disposed peripheral longitudinal face and a first lateral peripheral face and a second lateral peripheral face. The lateral faces include at least four continuous seal grooves, each of said seal grooves disposed in a pathway along each of the first peripheral longitudinal face and the first lateral face and second lateral face of each of the vane elements. At least four continuous seals are disposed in each of the at least four continuous seal grooves. A rotor includes a first end section and a second end section and a middle section disposed between the first end section and second end section, said first and second end section being formed about the axis of the rotor and having a diameter adapted to be received in the longitudinal bore portion of the housing, said middle section of the rotor having a first diameter formed about the axis of the rotor with a radial diameter smaller than the diameter of the end sections, said middle section further including a second diameter formed in the first diameter about the axis of the rotor as an opposing pair of substantially quarter-sectional recesses, the junctions of the first diameter and the second diameter defining a first, second, third and fourth longitudinal face on the middle section of the rotor. The actuator includes a first and second end assembly, each end assembly having a shaft bore adapted to receive an output shaft portion of the rotor and each of said first and second end assembly adapted to seal one of the end bore portions of the housing. A rotational fluid is provided at a first pressure and contacts the first and second opposing longitudinal face on the middle section of the rotor. A second rotational fluid is provided at a second pressure less than the first pressure and contacts the third and fourth opposing longitudinal face on the middle section of the rotor. The rotor is rotated in a first direction of rotation.
Various implementations can include some, all, or none of the following features. The single radial vane can extend an inward perpendicular distance from the two interior partial cylindrical surfaces such that portions of the continuous seals disposed in the continuous seal grooves in the longitudinal face of the single vane can contact the first diameter of the rotor and the half vanes can extend an inward perpendicular distance from the two partial cylindrical surfaces such that portions of the continuous seals disposed in the continuous seal grooves in the longitudinal face of the half vanes can contact with the second diameter of the rotor. The method can include stopping the rotation of the rotor by contacting a first longitudinal face of the middle section of the rotor with one of the opposing longitudinal faces. The method can include increasing the second pressure and reducing the first pressure until the second pressure is greater than the first pressure, rotating the rotor in an opposite direction to the first direction of rotation. The method can include stopping the rotation of the rotor in the opposite direction by contacting a second longitudinal face of the middle section of the rotor with one of the opposing longitudinal faces. The inwardly disposed vanes can isolate the rotational fluid into a first opposing pair of chambers and a second opposing pair of chambers, and the method can also include providing the first rotational fluid at the first pressure to the first opposing pair of chambers, and providing the second rotational fluid at the second pressure to the second opposing pair of chambers. The first lateral peripheral face can include a first fluid port formed therethrough and the second lateral peripheral face includes a second fluid port formed therethrough, and wherein providing the rotational fluid at a first pressure can be provided through the first fluid port and providing the rotational fluid at a second pressure can be provided through the second fluid port.
The systems and techniques described herein may provide one or more of the following advantages. In prior art designs of rotary actuators, corner seals can be a common source of fluid leakage between pressure chambers. Additionally, prior art rotary actuator housings are frequently assembled from one or more split casing segments that have seams that must be sealed. Leakage is possible from these housing seals. Cross-vane leakage can also occur in prior art rotary actuators. Leakage of hydraulic fluid in any of these manners may negatively impact performance, thermal management, pump sizing, and reliability of the hydraulic blocking rotary actuator. The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims.
This document describes examples of hydraulic blocking rotary actuators with continuous rotary piston seals. In general, by using continuous rotary piston seals between rotor assemblies and stator housings, the use of corner seals may be eliminated. Corner seals can be associated with undesirable effects, such as reduced mechanical performance, thermal management issues, increased pump size requirements, and reduced reliability.
The housing assembly 12 includes a cylindrical bore 18. As
The rotor 20 is able to rotate about 50-60 degrees in both a clockwise and counterclockwise direction relative to the stator housing assembly 12. Within the through bore 18, the stator housing 12 includes a first member 32 and a second member 34. The members 32 and 34 act as stops for the rotor 20 and prevent further rotational movement of the rotor 20. A collection of outside lateral surfaces 40 of the members 32 and 34 provide the stops for the rotor 20.
The first and second vanes 57a and 57b include a groove 56. As shown in
As seen in
By creating a fluid pressure differential between the pressure chambers 66 and the pressure chambers 68, the rotor 20 can be urged to rotate clockwise or counterclockwise relative to the stator housing assembly 12. In such designs, however, the corner seals 75 can be a common source of fluid leakage between the pressure chambers 66 and 68. Cross-vane leakage can also negatively impact performance, thermal management, pump sizing, and reliability of the hydraulic blocking rotary actuator 10.
In general, the actuator 1000 with a seamless casing provides the sealing capability generally associated with linear actuators with the general mechanical configuration of rotary actuators. The geometries of the components of the rotary actuator 1000 can be used to create various rotary actuators with the sealing capabilities generally associated with linear actuators. The design of the actuator 1000 implements a continuous seal that rides between two continuous and seamless surfaces. In general, this seamless casing allows for the construction of a rotary actuator in which hydraulic ports can be blocked to substantially lock and hold a selected position. Constant output torque can be generated by the application of hydraulic pressure to the axially perpendicular face of the rotary piston.
Referring to
In general, the actuator 1000 includes the collection of rotary pistons 1004a-1004d which translates rotary motion to the rotor 1008 by reacting to fluid pressure provided between the rotary pistons 1004a-1004d and housing 1002. The rotary pistons 1004a-1004d are separate pieces to allow for assembly into the housing 1002. Each of the rotary pistons 1004a-1004d uses a corresponding one of the continuous seals 1006a-1006d that rides uninterrupted on the inside of a pocket in the housing 1002. In some implementations, the seals 1006a-1006d can be O-rings, X-rings, Q-rings, D-rings, energized seals, or combinations of these and/or any other appropriate form of seals. The rotary pistons 1004a-1004d are keyed to the rotor 1008 to allow for proper spacing and to transmit the load from the rotary pistons 1004a-1004d to the rotor 1008. Radial forces resulting from operating pressure acting on the rotary pistons 1004a-1004d work to seat the rotary pistons 1004a-1004d against the rotor 1008 to maintain relative position. When installed, all rotary pistons 1004a-1004d rotate about the same axis, making them all substantially concentric to each other.
Referring now to
Referring now to
In general, the assembly of the rotary pistons 1004a-1004d with the housing 1002 involves orienting one of the rotary pistons, such as the rotary piston 1004b such that it will pass from outside of the housing 1002, through one of the openings 1022a-1022b, to the interior of the housing 1002. Once the rotary piston 1004b is fully inserted into the housing 1002, the rotary piston 1004 can be rotated within the interior space formed by the first surface 1024 and the pressure cavities 1028a-1028b. By positioning the rotary piston 1004b in the position illustrated in
Referring now to
Referring now to
Referring now to
The rotary pistons 1004a-1004d each include an elongated vane 1106. The elongated vanes 1106 are configured to extend from the rotary pistons 1004a-1004d, substantially at the diameter of the first surface 1024, to the second surface 1026. As such, the elongated vanes 1106 extend into the pressure chambers 1028a-1028b, bringing the continuous seals 1006a-1006d into sealing contact with the second surfaces 1026.
The elongated vanes 1106 are assembled in a back-to-back configuration, in which adjacent pairs of the elongated vanes form a pair of opposing rotary piston assemblies 1108. In the assembled configuration, the teeth 1102 of the rotor 1008 engage the slots 1104 of the rotary pistons 1004a-1004d, such that fluidic (e.g., hydraulic) forces applied to the rotary pistons 1004a-1004d can be transferred to the rotor 1008 and cause the rotor to rotate.
The continuous seals 1006a-1006d contact the second surfaces 1026 within the pressure chambers 1028a and 1028b and the first surfaces 1024 to form a pair of sealed, seamless opposing pressure chambers 1202a, and a pair of sealed, seamless opposing pressure chambers 1202a. In some implementations, opposing pressure chambers can be in fluid communication to balance the fluid pressures in opposing pairs of pressure chambers. In some implementations, the opposing pressure chambers can have equal surface areas as the rotor 1008 rotates within the housing 1002.
The opposing pressure chambers 1202a and 1202a defined by the stator housing assembly 1002 and the rotor assembly 1100 have substantially equal surface areas as the rotor assembly 1100 rotates within the housing 1002. In some implementations, such a configuration of equal opposing chambers supplies balanced torque to the rotor assembly 1100.
In the configuration illustrated in
Referring now to
Referring now to
The stator housing 1302 is generally formed as a cylinder with a central bore 1306. The rotor 1304 and the static rotary piston assemblies are assembled as an insert assembly 1400 which is then assembled with the stator housing 1302 by inserting the insert assembly 1400 into the through bore 1306 from a stator housing end 1308a or a stator housing end 1308b. The insert assembly 1400 is secured within the stator housing 1302 by assembling bushing assemblies 1310a and 1310b to the stator housing 1302. In the illustrated example, the bushing assemblies 1310a, 1310b include screw threads (not shown) that mate with screw threads (not shown) formed in the through bore 1306 to threadably receive the bushing assemblies 1310a, 1310b.
The stator housing 1302 also includes a collection of fluid ports 1312. The fluid ports 1312 are in fluid connection with fluid passages (not shown) formed through the body of the stator housing 1302. The fluid passages are discussed in the descriptions of
The insert assembly 1400 includes the rotor 1304, a static piston 1404a, and a static piston 1404b. The rotor 1304 includes end sections 1350, a first diameter 1422, and a second diameter 1424. The end sections 1350 are formed about the axis of the rotor 1304 with a diameter substantially similar to, but smaller than, that of the through bore 1306. The second diameter 1424 is formed about the axis of the rotor 1304 with a radial diameter smaller than that of the end sections 1350. The first diameter 1422 is formed about the axis of the rotor 1304 as a pair of substantially quarter sector recesses, in which the radial diameter of the first diameter 1422 is smaller than that of the second diameter 1424.
The static pistons 1404a, 1404b each include two continuous seal grooves 1406 which receive continuous seals 1408. The static pistons 1404a, 1404b are formed as substantially half-sector in the illustrated example, with an outside diameter approximately that of the bore 1306 such that the static pistons 1404a, 1404b will substantially occupy the space within the bore 1306 when assembled. The axial lengths of the static pistons 1404a, 1404b are selected such that the static pistons1404a, 1404b will substantially fill the axial length of the rotor 1304 between the end sections 1350 and cause sections of the continuous seals 1408, resting in the continuous seal grooves 1406, to be in sealing contact with the interior surfaces of the end sections 1350.
The static pistons 1404a, 1404b each include five primary interior surfaces; two interior walls 1420, an inner vane 1352, and two outer vanes 1354. The interior walls 1420 form an inner cylindrical surface which is concentric to the outer cylindrical surfaces of the static pistons 1404a, 1404b. Each interior wall 1420 is interrupted by the inner vane 1352 which extends radially inward perpendicular to the interior wall 1420. The interior walls 1420 are terminated at their semi-cylindrical ends by the outer vanes 1354, which extend radially inward perpendicular to the interior wall 1420.
The inner vane 1352 extends an inward distance from the interior wall 1420 such that sections of the continuous seals 1408, resting in the continuous seal grooves 1406, will be brought into sealing contact with the first diameter 1422 of the rotor 1304. The outer vanes 1354 extend an inward distance from the interior wall 1420 such that sections of the continuous seals 1408, resting in the continuous seal grooves 1406, will be brought into sealing contact with the second diameter 1424 of the rotor 1304. A portion of the continuous seals 1408 disposed in the continuous seal grooves 1406 on the lateral face of static pistons 1404a, 1404b are in sealing contact with interior lateral surfaces of the end sections 1350. When assembled, the rotor 1304, the static pistons 1404a, 1404b, and the continuous seals 1408 form four fluid pressure chambers. In some implementations, opposing pairs of fluid chambers can have equal surface areas as the rotor 1304 rotates within the housing 1302. In some implementations, an opposing pair of the fluid chambers can be adapted to be connected to an external pressure source and a second opposing pair of the fluid chambers can be adapted to be connected to a second external pressure source. These chambers are described further in the description of
In this configuration, axial portions of the continuous seals 1408 are brought into contact with the rotor 1304, and end portions of the continuous seals 1408 are brought into contact with the interior surfaces of the end sections 1350. The assemblage of the rotor 1304, the static pistons 1404a, 1404b, and the continuous seals 1408 form four pressure chambers 1702a, 1702b, 1704a, and 1704b. Opposing pair of pressure chambers 1702a and 1702b are in fluid communication with a fluid port 1712a, and opposing pair of pressure chambers 1704a and 1704b are in fluid communication with a first fluid port 1712b. In some implementations, the fluid ports 1712a and 1712b can be the fluid ports 1312 of
Fluid is applied to the fluid port 1712b, which fluidly connects to the pressure chambers 1704a, 1704b through a fluid passage 1812b. The pressure chambers 1702a, 1702b are fluidly connected to the fluid passage 1712a through a fluid port 1812a.
As fluid is applied to the fluid port 1712b, the pressure increases in pressure chambers 1704a, 1704b and fluid exhaust from fluid chambers 1702a, 1702b through fluid port 1712a to urge the rotor 1304 to turn in a clockwise direction.
As fluid continues to be applied to the fluid port 1712b, the rotor 1304 continues to rotate relative to the static pistons1404a, 1404b, until the rotor 1304 encounters a substantially clockwise rotational limit, a clockwise hard stop 1804. Referring now to
Although in
At step 1220, a stator housing (e.g., the stator housing 1002) is provided. The stator housing has a middle chamber portion including an opposing pair of arcuate ledges (e.g., hard stops 1204) disposed radially inward along the perimeter of the chamber, each of said ledges having a first terminal end and a second terminal end. In some implementations, the stator housing can be adapted for connection to a valve housing.
At step 1230, a rotational fluid is provided at a first pressure and contacting the first vane with the first rotational fluid. For example, hydraulic fluid can be applied through the fluid port 1210 to the chambers 1202a.
At step 1240, a rotational fluid is provided at a second pressure less than the first pressure and contacting the second vane with the second rotational fluid. For example, as the rotor assembly rotates clockwise, fluid in the fluid chambers 1202a is displaced and flows out through the fluid port 1212.
At step 1250, the rotor assembly is rotated in a first direction of rotation. For example,
At step 1260, the rotation of the rotor assembly is stopped by contacting the first terminal end of the first ledge with the first vane and contacting the second terminal end of the first ledge with the second vane. For example,
In some implementations, the rotor assembly can be rotated in the opposite direction to the first direction of rotation by increasing the second pressure and reducing the first pressure until the second pressure is greater than the first pressure. In some implementations, the rotation of the rotor assembly in the opposite direction can be stopped by contacting the first terminal end of the first ledge with the second vane and contacting the second terminal end of the first ledge with the first vane.
In some implementations, the first terminal end can include a first fluid port formed therethrough and the second terminal end can include a second fluid port formed therethrough. Rotational fluid at a first pressure can be provided through the first fluid port and rotational fluid at a second pressure can be provided through the second fluid port. For example, fluid can be applied at the fluid port 1210 and flowed to the chambers 1202a through fluid ports (not shown) formed in the hard stops 1204. Similarly, fluid can be applied at the fluid port 1212 and flowed through fluid ports (not shown) formed in the hard stops 1204.
With regard to the second embodiment, at step 1210, the rotor 1304 is provided. The rotor 1304 includes the end sections 1350 formed about the axis of the rotor 1304 with a diameter substantially similar to, but smaller than, that of the through bore 1306. The second diameter 1424 is formed about the axis of the rotor 1304 with a radial diameter smaller than that of the end sections 1350. The first diameter 1422 is formed about the axis as a pair of substantially diametrically opposed quarter sector recesses, in which the radial diameter of the first diameter 1422 is smaller than that of the second diameter 1424. In some implementations, the rotor 1304 can be configured to connect to the hinge line of a flight control surface.
At step 1220, a stator housing (e.g., the stator housing 1302) is provided. The housing 1302 is generally formed as a cylinder with a central bore 1306. The rotor 1304 and the static piston assemblies 1404a-1404b are assembled with the housing 1302 by inserting the rotor 1304 and the static pistons assemblies 1404a-1404b into the through bore 1306 from a housing end 1308a or a housing end 1308b.
At step 1230, a rotational fluid is provided at a first pressure and contacting the first inner vane side of a static piston while acting against the differential area created by the height difference between the first diameter 1422 and second diameter 1424 of the rotor 1304 with the first rotational fluid. For example, hydraulic fluid can be applied through the fluid port 1712b to the chambers 1704a.
At step 1240, a rotational fluid is provided at a second pressure less than the first pressure and contacting the second inner vane side of a second static piston while acting against the differential area created by the height difference between the first diameter 1422 and second diameter 1424 of the rotor 1304 with the second rotational fluid. For example, as the rotor 1304 rotates clockwise, fluid in the fluid chambers 1702a is displaced and flows out through the fluid port 1712a.
At step 1250, the rotor 1304 is rotated in a first direction of rotation. For example,
At step 1260, the rotation of the rotor 1304 is stopped by contacting an edge of the second diameter 1424 with the inner vane of the static piston. For example,
In some implementations, the rotor can be rotated in the opposite direction to the first direction of rotation by increasing the second pressure and reducing the first pressure until the second pressure is greater than the first pressure. In some implementations, the rotation of the rotor in the opposite direction can be stopped by contacting an edge of the second diameter 1424 and contacting the hard stop 1802.
In some implementations, the first terminal end can include a first fluid port formed therethrough and the second terminal end can include a second fluid port formed therethrough. Rotational fluid at a first pressure can be provided through the first fluid port and rotational fluid at a second pressure can be provided through the second fluid port. For example, fluid can be applied at the fluid port 1712a and flowed to the chambers 1702a through fluid ports formed in the hard stops 1804. Similarly, fluid can be applied at the fluid port 1712b and flowed through fluid ports formed in the hard stops 1802.
Although a few implementations have been described in detail above, other modifications are possible. Accordingly, other implementations are within the scope of the following claims.
Claims
1-27. (canceled)
28. A hydraulic blocking actuator comprising:
- a stator housing having a bore disposed axially therethrough;
- a first static piston assembly and a second static piston assembly, each static piston assembly having an outer longitudinal peripheral surface adapted to contact an inner wall of a portion of the stator housing, each static piston assembly including: two interior partial cylindrical surfaces, a single radial inwardly disposed vane positioned between the two interior partial cylindrical surfaces, and two radial inwardly disposed half vanes positioned at the distal ends of the two interior partial cylindrical surfaces, wherein the first static piston assembly and the second static piston assembly are disposed with one of the half vanes of the first static piston assembly adjacent longitudinally to one of the half vanes of the second static piston assembly and the other half vane of the first static piston assembly adjacent longitudinally to the other half vane of the second static piston assembly, and wherein each of the single vane and the half vanes has an inwardly disposed peripheral longitudinal face and a first lateral peripheral face and a second lateral peripheral face; at least two continuous seal grooves, each of said seal grooves disposed in a pathway along the peripheral longitudinal face and the first and second peripheral lateral faces of the single vane and the peripheral longitudinal faces and the first and second peripheral lateral faces of one of the half vanes; a continuous seal disposed in each of the at least two continuous seal grooves; and
- a rotor adapted to be received in the bore of the housing.
29. The actuator of claim 28 wherein the rotor includes a first end section and a second end section and a middle section disposed between the first end section and the second end section; said first and second end sections being formed about the axis of the rotor and having a diameter adapted to be received in the bore of the housing, said middle section having a first diameter formed about the axis of the rotor with a radial diameter smaller than the diameter of the end sections, said middle sections further including a second diameter formed in the first diameter about the axis of the rotor as an opposing pair of recesses.
30. The actuator of claim 28 wherein the single radial vane extends an inward perpendicular distance from the two interior partial cylindrical surfaces such that portions of the continuous seals disposed in the continuous seal grooves in the longitudinal face of the single vane will contact the first diameter of the rotor and the half vanes extend an inward perpendicular distance from the two partial cylindrical surfaces such that portions of the continuous seals disposed in the continuous seal grooves in the longitudinal face of the half vanes, will contact with the second diameter of the rotor.
31. The actuator of claim 28 further including first and second end bearing assemblies, each assembly having a shaft bore adapted to receive an output shaft portion of the rotor and each of said first and second end bearing assemblies adapted to seal each respective end bore portions of the housing.
32. The actuator of claim 31 wherein a portion of the continuous seals disposed in the continuous seal grooves on the lateral faces of the first static piston assembly and the lateral faces of the second static piston assembly are in sealing contact with interior surfaces of the first and second ends of the rotor.
33. The actuator of claim 30 wherein the single vane of the first static piston assembly and the single vane of the second static piston assembly are disposed opposite each other inside the middle bore portion of the rotor.
34. The rotary actuator of claim 33 wherein two adjacent half vanes are disposed opposite two other adjacent half vanes inside the middle bore portion of the stator housing.
35. The rotary actuator of claim 30 wherein the first static piston assembly and the second static piston assembly, with the rotor define four pressure chambers.
36. The actuator of claim 35 wherein opposing pressure chambers have equal surface areas as the rotor rotates within the housing.
37. The actuator of claim 28 wherein the output shaft is configured to connect in a hinge line connected to a flight control surface.
38. The actuator of claim 28 wherein the stator housing is adapted for connection to a fixed flight surface in a wing.
39. The actuator of claim 28 wherein the continuous seals are selected from the group consisting of an O-ring, an X-ring, a Q-ring, a D-ring, and an energized seal.
40. The actuator of claim 35 wherein a first opposing pair of the pressure chambers is adapted to be connected to a first external pressure source and a second opposing pair of the pressure chambers is adapted to be connected to a second external pressure source.
41. A method of rotary actuation comprising:
- providing a rotary actuator including: a stator housing having a bore disposed axially therethrough; a first static piston assembly and a second static piston assembly, each static piston assembly having an outer longitudinal peripheral surface adapted to contact an inner cylindrical wall of a portion of the stator housing, each static piston assembly including: two interior partial cylindrical surfaces, a single radial inwardly disposed vane positioned between the two interior partial cylindrical surfaces, and two radial inwardly disposed half vanes positioned at the distal ends of the two interior partial cylindrical surfaces, wherein the first static piston assembly and the second static piston assembly are disposed with one of the half vanes of the first static piston assembly adjacent longitudinally to one of the half vanes of the second static piston assembly and the other half vane of the first static piston assembly adjacent longitudinally to the other half vane of the second static piston assembly, and wherein each of the single vanes and the half vanes has a inwardly disposed peripheral longitudinal face and a first peripheral lateral faces and a second peripheral lateral face; at least two continuous seal grooves, each of said seal grooves disposed in a pathway along the peripheral longitudinal face and the first and second peripheral lateral faces of the single vane and the peripheral longitudinal face and the first and second peripheral lateral faces of one of the half vanes; a continuous seal disposed in each of the at least two continuous seal grooves; and a rotor adapted to be received in the bore of the housing, said rotor including a first end section and a second end section and a middle section disposed between the first end section and the second end section; said first and second end sections being formed about the axis of the rotor and having a diameter adapted to be received in the bore of the housing, said middle section having a first diameter formed about the axis of the rotor with a radial diameter smaller than the diameter of the end sections, said middle sections further including a second diameter formed in the first diameter about the axis of the rotor as an opposing pair of recesses, wherein junctions of the first diameter and the second diameter define first, second, third and fourth longitudinal faces on the middle section of the rotor;
- providing a first rotational fluid at a first pressure and contacting with the first rotational fluid at the first pressure the first and second longitudinal faces on the middle section of the rotor;
- providing a second rotational fluid at a second pressure less than the first pressure and contacting with the second rotational fluid at the second pressure the third and fourth longitudinal face on the middle section of the rotor; and
- rotating the rotor in a first direction of rotation.
42. The method of claim 41, wherein the single radial vane extends an inward perpendicular distance from the two interior partial cylindrical surfaces such that portions of the continuous seals disposed in the continuous seal grooves in the longitudinal face of the single vane will contact the first diameter of the rotor and the half vanes extend an inward perpendicular distance from the two partial cylindrical surfaces such that portions of the continuous seals disposed in the continuous seal grooves in the longitudinal face of the half vanes, will contact with the second diameter of the rotor.
43. The method of claim 41, further comprising stopping the rotation of the rotor by contacting a first one of the longitudinal faces of the middle section of the rotor with one of the single vanes of the static piston assemblies.
44. The method of claim 41, further including increasing the second pressure and reducing the first pressure until the second pressure is greater than the first pressure;
- rotating the rotor in an opposite direction to the first direction of rotation.
45. The method of claim 44, further including:
- stopping the rotation of the rotor in the opposite direction by contacting a second one of the longitudinal faces of the middle section of the rotor with one of the single vanes of the static piston assemblies.
46. The method of claim 41, wherein the single inwardly disposed vanes of the first and second static piston assemblies isolate the first and second rotational fluids into a first opposing pair of chambers and a second opposing pair of chambers, and the method further comprises providing the first rotational fluid at the first pressure to the first opposing pair of chambers, and providing the second rotational fluid at the second pressure to the second opposing pair of chambers.
47. The method of claim 41, wherein the first lateral peripheral face further includes a first fluid port formed therethrough and the second lateral peripheral face includes a second fluid port formed therethrough, and wherein providing the first rotational fluid at the first pressure comprises providing the first rotational fluid through the first fluid port and providing the second rotational fluid at the second pressure comprises providing the second rotational fluid through the second fluid port.
Type: Application
Filed: Feb 6, 2013
Publication Date: Aug 7, 2014
Patent Grant number: 8915176
Applicant: WOODWARD, INC. (Fort Collins, CO)
Inventors: Rhett S. Henrickson (Palmdale, CA), Robert P. O'Hara (Castaic, CA)
Application Number: 13/760,135
International Classification: F01D 9/00 (20060101);